Various different kinds of fasteners for fastening together sheet objects, such as sheets of paper, are known in the art. One class of such fasteners functions by applying a clamping force to the sheets to be fastened together, typically at one corner of a plurality of sheets. For example, the common paper clip and the binder clip or ‘fold-back’ clip function in this way. A disadvantage of the clamp type fastener is that it can become dislodged from the sheets by a simple sliding motion. Accordingly, movement of the fastened sheets relative to one another, such as that which may occur when a document is being read, may cause the fastener to slide off the sheets leaving them unfastened.
An alternative approach to the clamp type fastener is a fastener which secures a plurality of sheets together by piercing or puncturing the sheets to be fastened. For example, a metal staple is a well known fastener of this type. Staples are dispensed from a stapler which comprises an applicator portion disposed opposite a plate portion. Sheets to be fastened together are positioned between the applicator portion and the plate portion, and pressure exerted on the applicator portion against the stack of sheets causes a staple to be dispensed. The legs of the staple pierce the stack of sheets and are bent either toward or away from each other upon contact with the plate so as to secure the sheets together.
However, a drawback of the use of staples is that a separate applicator device, the stapler, is required to apply them. Additionally, the legs of the staple are not always reliably bent by the plate such that the sharp ends of the legs are embedded in the surface of the fastened papers. Accordingly, the ends of the legs may present an injury risk to a person handling the stapled papers. Furthermore, in the event that the papers need to be unfastened, a separate staple remover device is usually required to remove the staple, otherwise there is a further risk of injury to a user's hands.
Another type of fastener is the Treasury tag or India tag which generally comprises a piece of string with a bar of metal or plastic attached to each end. A stack of sheets may be fastened together by passing one of the bars through a hole formed in the stack of sheets using a hole punch. However, like stapling, fastening using this technique is inconvenient for the user because a separate device, in this case a hole punch, is required.
It is an aim of the present invention to provide a fastener for a sheet objects which substantially overcomes or mitigate at least some of the above-mentioned problems.